The reason is obvious. Considered in a physical sense, this passion is good; in a moral one, it is attended with every evil. In what does the morality of love consist? in vanity; vanity in the pleasure of conquest, an error which proceeds from our putting too high a value upon it; the vanity of desiring exclusive possession, of which jealousy, a passion so base that we are ashamed to own it, is the constant attendant; vanity in the very mode of enjoying, or even relinquishing the object of our desires, if the wish of separation originates with ourselves; but if, instead of forsaking, we are forsaken by the beloved object, the humiliation is dreadful! and the discovery that we have been duped and deceived, not unoften hurries us into despair.
From all these miseries brutes are free. They seek not to obtain pleasure where it is not to be found: guided by sentiment alone, they are never deceived in their choice; their desires are always proportioned to their power of gratification; they feel as much as they enjoy, and seek not to vary or anticipate them. But Man, in striving to invent pleasure, only depraves nature; in struggling to create sentiment, he perverts the intention of his being, and creates in his heart a vacuum which nothing can afterwards fill.
Every thing good in love belongs to the brutes as well as to man, and even they, as if this sentiment could never be pure, seem to have a small portion of jealousy. Among us, this passion always implies some distrust of ourselves, some distant knowledge of our own weakness, while brutes are never jealous but in proportion to their strength, ardour for, and propensity to pleasure. The reason is, that our jealousy depends on our ideas, and theirs on sentiment. Having once enjoyed, they desire to enjoy again; and feeling their strength, they drive away all that would occupy their place. Their jealousy is without reflection, they turn it not against the object of their love: of their pleasures alone are they jealous.
But are animals confined merely to those passions we have described? Are fear, rage, horror, love, and jealousy, the only durable affections they are capable of experiencing? To me it appears that, independent of these passions, which arise from their natural feelings, they have others, which are communicated to them by example, imitation, and habit. They have a kind of friendship, pride, and ambition, and though we may be convinced, that in all their operations there is neither reflection nor thought, yet as all their habits seem to imply some degree of intelligence, and to form the shade between them and man, it requires, in a peculiar manner, our strict examination.
Is there any thing exceeds the attachment of the dog to its master? On the grave that contained his dust has this animal been known to breathe its last. But (without quoting prodigies or heroes) with what fidelity does he accompany, follow, and defend his master! With what eagerness does he solicit his caresses! With what docility does he obey him! With what patience does he suffer his bad humours, and his frequently unjust corrections! With what mildness and humility does he endeavour to be restored to favour! What emotion and anxiety does he express when his master is absent! and what joy when he returns!—From all these circumstances it is possible not to distinguish true marks of friendship? Even among the human species it is expressed in characters of superior energy.
This friendship is the same as that of a female for her favourite bird, or of a child for its play-thing. Both are equally blind and void of reflection; that of the animal is more natural, since it is founded on necessity, while that of the other is only an insipid amusement, in which the mind in no degree partakes These childish habits subsist merely by idleness, and are more or less strong as the brain is more or less vacant.
Real friendship, however, supposes the power of reflection; it is of all attachments the most worthy of man, and the only one by which he is not degraded. Friendship flows from reason alone. It is the mind of a friend which we love, and to love a mind it is necessary to have one, and to have made use of it in the attainment of intelligence, and in comparing the congeniality of different minds. By friendship, then, not only is implied the principle of knowledge, but also, from reflection, the actual exercise of that principle.
Thus, while friendship belongs solely to man, attachment may be possessed by animals; as sentiment alone is sufficient to attach them to persons whom they often see, and by whom they are fed and nourished. The attachment of females to their young is produced by the trouble they have had in carrying them in the womb, and in producing and giving them suck. If, among birds, some males seem to have an attachment to their young, and to take care of the females while they are sitting, it is because they have been employed in the construction of the nest, and continue to enjoy pleasure with their females long after impregnation. Among other animals, with whom the season of love is short, that elapsed, the male is no longer attached to the female; where there is no nest, no employment, in which they may be mutually engaged, the fathers, like those of Sparta, have no care for their progeny.
The pride and ambition of animals proceed from their natural courage; that is, from their sense of their strength, agility, &c. Large ones hold the small in defiance, and seem to contemn their insulting audacity. This courage may also be improved by instruction, for, reason alone excepted, of every thing are brute animals susceptible. In general they will learn to perform the same action a thousand times; to do without intermission what they did by intervals; to continue for a length of time what they at first ended in a moment; to do cheerfully what at first was the effect of force; to do by habit what they once have done by chance; and to perform of themselves what they have seen done by others. Of all the operations of the animal machine imitation is the most admirable. It is its most delicate and most extensive mobile, and exhibits the truest copy of thought, and though the cause of it in animals is altogether material, yet by its effects our wonder is excited. Men never more admire an ape than when they see it imitate the actions of men. In fact it is not easy to distinguish some copies from some originals. Besides, there are so few who can distinctly perceive the difference between a reality and a counterfeit, that to the bulk of mankind an ape must always excite astonishment.